The phylum Annelida are the segmented worms. The three main groups are the Polychaeta, such as the lugworms, some of which are free living but others living in tubes, the Oligochaeta such as the earthworm and the Hirudinea, which are the leeches. All have bodies supported by internal pressure, a hydrostatic skeleton, and are divided into segments.
Information on these organisms and their phylogenetic relationships from the Tree of Life Web Project, with photographs of several species.
The Illinois Natural History Survey Annelida Collection is one of the largest state collections of freshwater oligochaetes in the USA, holding more than 300,000 specimens.
Introduction to the Annelida, the segmented worms.
The segmented worms, including earthworms, polychaete worms, and leeches.
Provides information on this diverse phylum, the characteristics of worms, and information on the three classes, Polychaeta, Aelosomata and Clitellata.
Photographs and links to other worm pages, from the University of Hawaii at Manoa.
Thanks to DMOZ, which built a great web directory for nearly two decades and freely shared it with the web. About us